An especially well-received releasable electrical connector includes plug and receptacle parts which can be mated together to effect connection between pins and sockets carried by the respective parts. By virtue of the heavy metal shells, when the two connector halves are mated, there is a relatively good protection against external electromagnetic fields inducing undesirable voltages in the wires and thus via the shielded cables into electrical equipment to which the cables are connected. However, when the plug and receptacle are separated, the exposed interconnection electrodes are readily influenced by environmental electromagnetic fields.
In U.S. Pat. No. 3,550,065 there is described the use of a metal plate for being received onto the open end of a connector half in which the socket electrodes are mounted, which plate has openings via which pins from the other connector half can pass for mating interconnection with the sockets. This grid plate or shield is electrically connected with the connector metal casing or shell and serves to act as a shield for reflection and absorption of external electromagnetic energy thereby preventing or substantially reducing the induction of electric currents in the connector sockets and thus into the cable wires and equipment interconnected therewith.
Although the technique and structure of the shield described in the referenced United States patent is generally effective, the electromagnetic environments being encountered today are becoming increasingly severe in terms of both intensity and frequency, and this is especially true in connection with military components necessitating the adoption of even better shielding means. For example, in the event of a nuclear explosion an electromagnetic pulse (EMP) is produced which can literally by itself damage or destroy electrical and electronic equipment at distances from the blast sufficient for safety from the actual blast effects.